The retiring leader of the Anglican communion leaves an ambiguous legacy.

So last autumn's rumours were mainly true. Rowan Williams is to step down as Archbishop of Canterbury[3] at the end of the year, though not it seems to take up a full-time academic job as a professor of theology. Rather, he will occupy a comfortable sinecure as Master of Magdalene College, Cambridge; a post that brings little in the way of responsibility but does afford some lovely views over the river Cam. At sixty-two, he will still be younger than many of his predecessors were when they were appointed, to say nothing of Pope Benedict XVI -- shortly to celebrate his eighty-fifth birthday and old enough to be, in some bizarre parallel universe, Dr Williams' father.

Attention will no doubt soon turn to the matter of the succession. The Archbishop of York, John Sentamu, is the clear favourite, which probably means that he will not get the job. There are signs of an advanced "stop Sentamu" campaign already. It's difficult to say more at this point, not least because of the opaque system of appointment by the Crown Nominations Committee, which I have criticised before[3]. I think it's safe to say, though, that it won't be Giles Fraser.

During his tenure as Archbishop of Canterbury, Rowan Williams has pulled off the rare feat of being controversial without being particularly outspoken. His most memorable interventions -- such as his notorious 2008 speech which appeared to suggest that the recognition of Sharia law in Britain was both inevitable and right -- have been couched in abstruse and often equivocal language. He has perfected the art of sitting on barbed-wire fences, seeming almost to find the resulting discomfort a source of intellectual and moral inspiration.

At best, Williams' contributions to the national debate have been insightful and even pointed. I would single out, for example, an article he wrote for the Times[4] at the height of the Parliamentary expenses scandal in 2009, warning of the dangers that "systematic humiliation of politicians" posed for the health of democracy and pointing out that regulation was no substitute for integrity.

But a man whose theology has always been characterised by nuance and ambiguity, who tends to see eleven sides to every question, has never looked comfortable in a public arena that prioritises confrontation. And it's notable that he has tended to be more forthright, even impassioned, in his political pronouncements (see for example the leading article he wrote[5] as guest editor of the New Statesman last year) than when talking about purely religious matters. Perhaps he just feels more ambiguity in his own area of professional expertise, where he has thought longer and more deeply.

He leaves a Church of England, and an Anglican Communion, at least as riven on questions of sexuality and gender as when he was appointed a decade ago. This isn't his fault, although critics complain that he has tended to put unity above principle and failed to give strong leadership. The position taken by most Anglican churches in Africa, which see homosexuality as inherently sinful (at best) is in the end irreconcilable with the liberal views which predominate in North America and increasingly (though far from uniformly) in the Church of England itself. The latest scheme for papering over the cracks -- the so-called Anglican Covenant, on which Williams has staked much of his personal authority -- is in deep trouble; seventeen C of E dioceses have already rejected it.

By announcing his resignation now, rather than (as had been expected) after this summer's Jubilee celebrations, Williams will at least avoid being seen to have quit in response to a humiliating failure. But he may well still be in post when the General Synod gives its final approval for the consecration of women as bishops. This would be a proud legacy to take his leave on. Yet the instinctively Anglo-Catholic Williams will also be acutely conscious of the implications of the move for the Church of England (facing yet more splits and Romeward defections) and for wider efforts towards Christian unity. The question is another of the many circles that his immensely subtle theological mind has never quite managed to square.

He will, though, be relieved to escape the constant criticism and scrutiny to which he has been subjected in the past decade. There's nothing unusual in an Archbishop of Canterbury attracting dismissive press coverage, of course. Indeed it's a great British tradition. Both of his immediate predecessors, in their different ways, were at times figures of ridicule. And it might be said that Lord Carey's subsequent career as a moral and ecclesiastical pundit in the News of the World and more recently the Daily Mail has proved no more helpful to Dr Williams than was Lady Thatcher to John Major. I'd be very surprised if his successor, whoever he is, faced similar discomforting interventions from the Master of Magdalene.